We will study the antiviral properties of antibody dependent cellular cytotoxicity (ADCC) antibodies and CD8+ cells in HIV+ pregnant mothers and HIV infected children while on ACTG protocols. The ADCC assays employ target cells infected with the predominant autologous maternal viral strains and her infected infant's viral strain. We will determine if maternal-fetal transmission is associated with absence of maternal antibody to the specific viral strain transmitted to her infant and conversely if transmission is prevented in the presence of maternal ADCC antibodies to her dominant strain. We will also determine if HIV hyperimmune intravenous immunoglobulin (HIVIG) give to the mother during pregnancy provides adequate ADCC antibody levels to the mother and to her newborn infant. We will also identify cellular defects in ADCC effector function during pregnancy, including deficient PMN and monocyte effector function. Utilizing a new assay in which isolated CD8 cells inhibit proliferation of autologous CD4 viral replication, we will determine if HIV+ children with a favorable course (i.e., minimal progression) have enhanced CD8 inhibitory activity, if antiviral therapy enhances this inhibition and if autologous CD8 inhibitory cells can be expanded in vitro for reinfusion in HIV+ children unresponsive to conventional therapy.